//获取滚动条当前的位置
export function getScrollTop() {
  var scrollTop = 0;
  if (document.documentElement && document.documentElement.scrollTop) {
    scrollTop = document.documentElement.scrollTop;
  } else if (document.body) {
    scrollTop = document.body.scrollTop;
  }
  return scrollTop;
}

//获取当前可视范围的高度
export function getClientHeight() {
  var clientHeight = 0;
  if (document.body.clientHeight && document.documentElement.clientHeight) {
    clientHeight = Math.min(
      document.body.clientHeight,
      document.documentElement.clientHeight
    );
  } else {
    clientHeight = Math.max(
      document.body.clientHeight,
      document.documentElement.clientHeight
    );
  }
  return clientHeight;
}

//获取文档完整的高度
export function getScrollHeight() {
  return Math.max(
    document.body.scrollHeight,
    document.documentElement.scrollHeight
  );
}
